Conventionally, this type of crushing equipment has been proposed to include a pair of arms having crushing blades and having middle portions pivotally mounted on side plates, vertically elongated slots formed on the side plates and extending vertically along the vertical axis, trunnion pins protruding from side walls of a bidirectional hydraulic cylinder in a direction to intersect the vertical axis and slidably engaging the vertically elongated slots, and a pair of piston rods which are disposed on both sides of the hydraulic cylinder and movable to extend and to retract with respect to the vertical axis, and which are pivotally connected to the rear ends of the arms, respectively. (For example, see Japanese Utility Model Publication No. 2-11709 and Japanese Utility Model Publication No. 3-26846)
However, in the above conventional equipment, the hydraulic cylinder is mounted on the side plates by supporting with the trunnion pins, and therefore, if external impact forces are applied to the arms having the crushing blades when the hydraulic cylinder is in its stroke end, the trunnion pins directly receive the impact forces, and the impact forces are further transmitted to the bidirectional hydraulic cylinder having the extending trunnion pins as well as to the side plates, and an undesired impact force is applied to an arm of a work vehicle, etc. through a bracket for mounting the whole crushing equipment on the arm. The arms having the crushing blades are adapted not only for contacting or striking against a material to be crushed during a crushing operation but also for moving the crushed materials scattered on the ground, and therefore, external forces are frequently applied to the arms, thus causing various adverse effects.
It is accordingly an object of the present invention to provide crushing equipment which is operable to relieve external forces applied to crushing members so as to avoid as much adverse effect as possible on a fluid-pressure cylinder, a frame, etc.